Recently, as an image recording material, the materials to form color images are particularly the mainstream, and specifically, inkjet recording materials, thermal transfer image recording materials, recording materials using an electrophotographic system, transfer silver halide photosensitive materials, printing inks, recording pens and the like have been actively utilized. In addition, color filters are used in LCD (liquid crystal display) and PDP (plasma display panel) for displays and in electronic parts such as CCD (charge coupled device) for photographing equipments. In these color image recording materials and color filters, a coloring matter (dye or pigment) of 3 primary colors for the so-called additive and subtractive color mixing processes is used to reproduce or record full color images. However, there is actually no coloring matter which has absorption characteristics providing a desired color reproduction area and can tolerate various use conditions, whereby improvement thereof is strongly required.
The inkjet recording method has been rapidly prevailing and further developing due to its low material cost, possibility of rapid recording, less noise in recording and also easiness of color recording. The inkjet recording method includes the continuous method of continuously discharging ink droplets and the on-demand method of discharging said droplets responding to an image information signal. The discharging method includes a method of discharging ink droplets by applying pressure with piezoelectric elements; a method of discharging ink droplets by generating bubbles in ink by heat; a method by using ultrasonic waves; a method of sucking and discharging ink droplets by electrostatic force; or the like. In addition, examples of the ink suitable for inkjet recording include water-based inks, oil-based inks, solid (melting-type) inks and the like.
The performance required for the coloring matter used in inks suitable for such inkjet recording are good solubility or dispersibility in solvents, ability of high density recording, good hue, good fastness to light, heat and active gases (oxidizing gases such as NOx and ozone, and in addition, SOx and the like) in the environment, excellent durability against water and chemicals, good fixation to record-receiving materials resulting in no bleeding, excellent storage stability as an ink, no toxicity, and also inexpensive availability, and the like. In particular, a cyan coloring matter having a good cyan hue, allowing recorded matters with a high print density and giving excellent fastnesses of recorded image, for example, light fastness (durability to light), ozone fastness (durability to ozone gas) and moisture fastness (durability under high humidity) is strongly desired.
As a water-soluble cyan coloring matter used for inks suitable for inkjet recording, a phthalocyanine-based coloring matter and a triphenylmethane-based coloring matter are typical. The typical phthalocyanine-based coloring matter reported and used in the widest range includes phthalocyanine derivatives classified into the following A to H:    A: Known phthalocyanine-based coloring matter having C.I. (color index) numbers such as Direct Blue 86, Direct Blue 87, Direct Blue 199, Acid Blue 249, Reactive Blue 71 or the like;    B: Phthalocyanine-based coloring matter described in Patent Literatures 1 to 3 and the like,[for example, a mixture of Cu-Pc-(SO3Na)m(SO2NH2)n; m+n=1 to 4] (Pc represents phthalocyanine residue, as is the same hereinafter);    C: Phthalocyanine-based coloring matter described in Patent Literature 4 and the like,[for example, Cu-Pc-(CO2H)m(CONR1R2)n; m+n=a number of 0 to 4];    D: Phthalocyanine-based coloring matter described in Patent Literature 5 and the like,[for example, Cu-Pc-(SO3H)m(SO2NR1R2)n; m+n=a number of 0 to 4, and m≠0];    E: Phthalocyanine-based coloring matter described in Patent Literature 6 and the like,[for example, Cu-Pc-(SO3H)l(SO2NH2)m(SO2NR1R2)n; l+m+n=a number of 0 to 4];    F: Phthalocyanine-based coloring matter described in Patent Literature 7 and the like,[for example, Cu-Pc-(SO2NR1R2)n; n=a number of 1 to 5];    G: Phthalocyanine-based coloring matter described in Patent Literatures 8, 9 and 12 and the like,[phthalocyanine compound in which the substitution position of the substituent is controlled, phthalocyanine-based coloring matter in which a substituent is introduced at the beta-position];    H: Benzo pyridoporphyrazine-based coloring matter having a pyridine ring and a benzene ring, described in Patent Literatures 10, 13 to 21 and the like;    I: Phthalocyanine-based coloring matter described in Patent Literature 11 and the like,[for example, Cu-Pc-(SO3H)a(SO2NR1R2)b(SO2NH—X—NH-(4-Y-6-Z-1,3,5-triazin-2-yl))c; a+b+c=a number of 2 to 4].
The phthalocyanine-based coloring matter typified by Direct Blue 86 or Direct Blue 199 which are usually used widely at present has a characteristic of being excellent in light fastness compared with magenta coloring matters and yellow coloring matters which are generally known. The phthalocyanine-based coloring matter has a greenish hue under acidic conditions, whereby it is not very preferable as a cyan ink. Therefore, it is preferable that these coloring matters are used under neutral to alkaline conditions when used as a cyan ink. However, although the ink to be used is neutral to alkaline, it is possible that the hue of a printed matter is greatly changed when the record-receiving material to be used is an acidic paper.
In addition, when the phthalocyanine-based coloring matter is used as a cyan ink, the hue of a printed matter is discolored greenish and also color fading occurs due to oxidizing gases such as nitrogen oxide gas and ozone which are often concerned nowadays as an environmental problem, whereby the print density is concurrently reduced.
On the other hand, the triphenylmethane-based coloring matter has a good hue but is very inferior in light fastness, ozone fastness and moisture fastness.
From here on, as the application field of inkjet recording is widespread and inkjet recording is widely used in articles on exhibition for advertisement and the like, the ink used there will be more and more strongly required to have a good hue and to be inexpensive, and further, there will be more opportunities for coloring matter and ink to be exposed to light and oxidizing gases in the environment, whereby it is strongly required in particular to have a good hue and to be excellent in light fastness, oxidizing gas fastness, and moisture fastness. The term “oxidizing gas” referred here means gas existing in the air and having oxidizing effect. The term “oxidizing gas fastness” means durability to the phenomenon that coloring matter (dye) of recorded image on or in recorded paper is reacted with oxidizing gas, resulting in discoloration or fading of recorded image. Among oxidizing gases, ozone gas is particularly regarded to be the main causative matter promoting the discoloration or fading phenomenon of inkjet recorded images. This discoloration or fading phenomenon is characteristic of inkjet recorded images, whereby improvement of ozone gas fastness is an important technical challenge in this field. However, It is considered difficult to develop a cyan coloring matter (for example, phthalocyanine-based coloring matter) and a cyan ink satisfying these requirements at a high level. In the past, phthalocyanine-based coloring matters or benzo pyridoporphyrazine coloring matters to which fastness to ozone gases is imparted are disclosed in Patent Literatures 3, 8 to 12 and 14 to 17, and some are considerably excellent in all qualities of hue, print density, light fastness, ozone gas fastness, moisture fastness, no-bronzing phenomenon and the like, but there are some with an optimistic evaluation of hue and the like, whereby the requirements of the market have not been sufficiently satisfied.    [Patent Literature 1] Japanese Patent Laid-Open No. 62-190273 A    [Patent Literature 2] Japanese Patent Laid-Open No. 7-138511 A    [Patent Literature 3] Japanese Patent Laid-Open No. 2002-105349 A    [Patent Literature 4] Japanese Patent Laid-Open No. 5-171085 A    [Patent Literature 5] Japanese Patent Laid-Open No. 10-140063 A    [Patent Literature 6] National Publication of International Patent Application No. 11-515048 A    [Patent Literature 7] Japanese Patent Laid-Open No. 59-22967 A    [Patent Literature 8] Japanese Patent Laid-Open No. 2000-303009 A    [Patent Literature 9] Japanese Patent Laid-Open No. 2002-249677 A    [Patent Literature 10] Japanese Patent Laid-Open No. 2003-34758 A    [Patent Literature 11] Japanese Patent Laid-Open No. 2002-80762 A    [Patent Literature 12] WO 2004/087815    [Patent Literature 13] WO 2002/034844    [Patent Literature 14] Japanese Patent Laid-Open No. 2004-75986 A    [Patent Literature 15] WO 2007/091631    [Patent Literature 16] WO 2007/116933    [Patent Literature 17] WO 2008/111635    [Patent Literature 18] WO 2002/088256    [Patent Literature 19] WO 2005/021658    [Patent Literature 20] Japanese Patent Laid-Open No. 2005-179469 A    [Patent Literature 21] Japanese Patent Laid-Open No. 2005-220253 A